Skylights are used to illuminate buildings in a pleasing and energy-conserving way. Tubular skylights such as those made by the present assignee typically have a roof-mounted transparent cover or dome, a light conveying assembly extending down from the dome into the building to a ceiling, and a light diffuser plate covering the bottom of the assembly at the ceiling. The assembly can be tubular, or it can be rectangular or some other geometry if desired.
It is sometimes desirable to stop light from being transmitted through the skylight, e.g., when a person wishes to darken a room during the day. The present invention understands that one way to do this would be to provide a disk-shaped flapper in the light conveying assembly that can be turned parallel to the assembly axis to permit light to pass, and perpendicular to the axis to block light.
The present invention further understands, however, that flapper assemblies used in, e.g., air conditioning ducts are less than optimum in skylight applications. For one thing, a flapper assembly must include a mounting segment in which the flapper turns, with the mounting segment being installed in the passageway sought to be selectively blocked. In the skylight context this means that the segment, which must not only be as wide as the diameter of the flapper but also as long as the flapper diameter to adequately house the flapper, can be excessively long, causing substantial interference during installation in an existing skylight. Moreover, as understood herein many skylight systems are sold world wide, which means that any motor power supply that might be used to allow for electrical operation of the flapper must be capable of using a wide range of voltages. Absent such a “universal” power supply, multiple power supplies must be provided from which a selection can be made to tailor the skylight to the voltage supply capabilities for any particular location of sale.